JP5290382B2 - Deposition equipment - Google Patents

Description

  The present invention relates to a film forming apparatus, and more particularly to a film forming apparatus that deposits a fine film forming material to form a film.

  Transparent conductive films are widely used in fields such as semiconductors, displays, and solar cells. As the transparent conductive film, those made of metal oxides such as STO (strontium titanate) and ITO (Sn-doped indium oxide) are mainly used. The transparent conductive film is generally formed using a sputtering method, a vapor deposition method, a metal organic chemical vapor deposition method using an organic metal compound, or the like.

  In the sputtering method and the vapor deposition method, since a film is formed by a vacuum process, an equipment for forming and maintaining a vacuum atmosphere such as a vacuum vessel is required. In the organometallic chemical vapor deposition method, since the organometallic compound used as a raw material has explosiveness and toxicity, a highly confidential facility is required. For this reason, in order to perform the film forming method described above, an expensive film forming apparatus is required.

  Therefore, a mist method has been proposed as a film forming method different from the conventional one. The mist method is a method of forming a film by atomizing a solvent containing a raw material metal as a solute and spraying it on a substrate.

  In the mist method, a film can be formed at atmospheric pressure, so that no manufacturing equipment such as a vacuum vessel and pumps is required. In addition, since a dangerous substance such as an organometallic compound is not used in the mist method, an inexpensive film forming apparatus with a simple configuration can be used.

  As a prior document disclosing a thin film forming apparatus using a mist method, there is JP-A-5-221613 (Patent Document 1). In the thin film forming apparatus described in Patent Document 1, a fixing unit is fixed to a chamber, a substrate is fixed on the fixing unit, and a deposition surface of the substrate is set to face a bottom surface of the chamber. . A film-forming material is coated on the substrate surface from below to above through the nozzle opening. A gas exhaust means is provided below the substrate installation portion of the chamber to exhaust the reaction gas.

JP-A-5-221613

  In order to continuously form different types of films on a substrate, it is necessary to arrange a plurality of film forming chambers. When a plurality of film forming chambers are provided, different types of mist are introduced into the respective film forming chambers. Therefore, different mists may be mixed in the film formation chamber from other adjacent film formation chambers. In this case, the quality of the film formed on the substrate is degraded.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a film forming apparatus capable of continuously forming a plurality of films on a substrate with high quality.

  A film forming apparatus according to the present invention includes a transfer unit that transfers a substrate along a transfer path, a plurality of film forming chambers that are arranged in the transfer path, and an adjacent film forming chamber among the plurality of film forming chambers. A heating furnace that surrounds and heats a substrate passing through a plurality of film forming chambers and is positioned in a tunnel shape along the transfer path so as to connect each other; and an exhaust means that exhausts the inside of each of the plurality of film forming chambers Is provided. Each of the plurality of film forming chambers includes a housing and a spray mechanism that sprays mist obtained by forming the film forming material into fine particles in the housing. The housing has an exhaust port located on one side wall and connected to the exhaust means, and has an open portion in the heating furnace facing the substrate that sequentially passes through the plurality of film forming chambers. Mist flows from the spray mechanism through the opening to the exhaust port in each of the plurality of film forming chambers. The exhaust flow rate from the exhaust port by the exhaust means is larger than the inflow flow rate into the housing.

  In one embodiment of the present invention, each of the plurality of film formation chambers further includes an introduction port located on one side wall of the housing for introducing a carrier gas for sending mist onto the substrate. The exhaust flow rate is not less than 3 times and not more than 10 times the total flow rate of the flow rate of the mist sprayed from the spray mechanism and the flow rate of the carrier gas introduced from the introduction port.

  In one form of this invention, a spray mechanism sprays the mist which atomized the film-forming material with the compressed air.

  In one form of the present invention, the spray mechanism is composed of a plurality of spray nozzles each having a spray port for spraying mist. The spray ports of the plurality of spray nozzles face the substrate and are spaced apart from each other in a direction intersecting the substrate transport direction in plan view.

  In one embodiment of the present invention, the film forming chamber further includes a blower mechanism that directs the mist sprayed from the spray mechanism toward the end portion of the substrate in the above-described direction intersecting the substrate transport direction in plan view.

  In one form of this invention, a ventilation mechanism consists of an air nozzle which has a some jet nozzle which ejects compressed air. The plurality of jet nozzles are positioned around the spray nozzles of the spray nozzles that face the substrate and are located at both ends of the plurality of spray nozzles in plan view.

  According to the present invention, a plurality of films can be continuously formed on a substrate with high quality.

It is a side view which shows the structure of the film-forming apparatus which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the structure of the film-forming chamber contained in the film-forming apparatus which concerns on the embodiment. It is the figure which looked at the film-forming chamber of FIG. 2 from the arrow III direction. It is a schematic diagram which shows the external shape of the spray area | region of the spray nozzle used for the film-forming apparatus which concerns on the embodiment. It is a graph which shows the relative spraying intensity in the longitudinal direction of the spray area | region of the spray nozzle which concerns on the embodiment. It is a graph which shows the relative spraying intensity in the transversal direction of the spray area | region of the spray nozzle which concerns on the embodiment. It is a graph which shows the comparative spraying intensity | strength in the longitudinal direction of a spray area | region at the time of arrange | positioning 11 spray nozzles so that the longitudinal direction of each spray area | region may become a line with a pitch of 100 mm. It is a graph which shows the comparative spraying intensity | strength in the longitudinal direction of a spraying area | region at the time of arrange | positioning so that the longitudinal direction of each spraying area | region may become a line with nine spray nozzles with a pitch of 120 mm. It is a graph which shows the comparative spraying intensity | strength in the longitudinal direction of a spray area | region at the time of arrange | positioning so that the longitudinal direction of each spray area | region may be in a line with eight spray nozzles as pitch. It is sectional drawing which shows the structure of the spraying mechanism and ventilation mechanism of the film-forming apparatus which concern on Embodiment 2 of this invention. It is the figure which looked at the spray mechanism and ventilation mechanism of FIG. 10 from the arrow XI direction. It is a graph which shows distribution of the arrival amount of mist in the longitudinal direction of the spray field arranged in a line. It is a graph which shows distribution of the sheet resistance value of the board | substrate in the direction orthogonal to a conveyance direction. It is a graph which shows the relationship between a film thickness and a sheet resistance value. It is a graph which shows the relationship between a film thickness and light transmittance. It is a graph which shows the relationship between a film thickness and a haze rate.

  First, regarding the film formation of a transparent conductive film used for a thin film solar cell or the like, the influence of the film thickness on various performances will be described.

  FIG. 14 is a graph showing the relationship between the film thickness and the sheet resistance value. FIG. 15 is a graph showing the relationship between film thickness and light transmittance. FIG. 16 is a graph showing the relationship between film thickness and haze ratio. In FIG. 14, the vertical axis represents the sheet resistance value (Ω / □), and the horizontal axis represents the film thickness (nm). In FIG. 15, the vertical axis indicates the light transmittance (%), and the horizontal axis indicates the film thickness (nm).

  In FIGS. 14 to 16, the experiment data when the alkali barrier layer is provided between the substrate and the transparent conductive film is “◯”, the approximate line thereof is a solid line, and the experiment when the alkali barrier layer is not provided. Data is indicated by “x”, and its approximate line is indicated by a dotted line. Moreover, the approximate line in FIG. 16 has shown the approximate line of the upper limit of each data, and a lower limit.

  As shown in FIG. 14, the sheet resistance value decreases as the film thickness of the transparent conductive film increases. As shown in FIG. 15, the light transmittance decreases as the film thickness of the transparent conductive film increases. As shown in FIG. 16, the haze rate increases as the film thickness of the transparent conductive film increases. In the sheet resistance value, a difference was recognized depending on the presence or absence of the alkali barrier layer even when the film thickness of the transparent conductive film was the same.

  As described above, the film thickness of the transparent conductive film is an important factor affecting the performance of the thin film solar cell. Therefore, it is desirable that the film thickness of the transparent conductive film formed on the substrate is uniform.

  Hereinafter, the film forming apparatus according to Embodiment 1 of the present invention will be described. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated. In the present embodiment, film formation of a transparent conductive film used for a thin film solar cell will be described as an example, but the present invention can be applied to film formation of various films.

(Embodiment 1)
FIG. 1 is a side view showing a configuration of a film forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view showing a configuration of a film forming chamber included in the film forming apparatus according to the present embodiment. FIG. 3 is a view of the film forming chamber of FIG. 2 as viewed from the direction of arrow III.

  As shown in FIG. 1, a film forming apparatus 10 according to Embodiment 1 of the present invention includes an input unit 11 into which a substrate 200 is input, a preheating unit 12 in which the substrate 200 is preheated, and a substrate 200 that is subjected to a film forming process. A film forming unit 13, a slow cooling unit 14 for cooling the substrate 200, and a take-out unit 15 for taking out the substrate 200.

  As shown in FIGS. 1 to 3, the film forming apparatus 10 includes a transfer conveyor 110 that is a transfer unit that transfers the substrate 200 along the transfer path. The conveyor 110 is provided across the input unit 11, the preheating unit 12, the film forming unit 13, the slow cooling unit 14, and the takeout unit 15.

  The conveyor 110 includes a conveyor belt 111 on which the substrate 200 is placed, a pulley 112 around which the conveyor belt 111 is wound, a drive shaft 113 that drives the pulley 112, and a motor (not shown) that applies power to the drive shaft 113. It consists of and. The conveyor belt 111 is made of heat-resistant metal or resin.

  The substrate 200 is transported in the direction indicated by the arrow 114 by the transport conveyor 110. That is, in the film forming apparatus 10 according to the present embodiment, the transport path of the substrate 200 is linear in plan view. However, the conveyance path is not limited to a straight line, and the conveyance path may be bent in a plan view or may be a curved line.

  The film forming apparatus 10 includes a plurality of film forming chambers 100 (100a, 100b, 100c, 100d) positioned so as to be aligned in the transfer path. Specifically, a film formation chamber 100a, a film formation chamber 100b, a film formation chamber 100c, and a film formation chamber 100d are provided in this order from the upstream side in the transport direction of the substrate 200. In the present embodiment, four film formation chambers 100 (100a, 100b, 100c, and 100d) are provided, but a plurality of film formation chambers 100 may be provided.

  Further, the film formation apparatus 10 is positioned in a tunnel shape along the transfer path so as to connect adjacent film formation chambers among the plurality of film formation chambers 100, and the substrate 200 that sequentially passes through the plurality of film formation chambers 100. A heating furnace 120 is provided for surrounding and heating. As shown in FIG. 3, the lower portion of the housing 150 is covered with the heating furnace 120.

  An opening is provided in the upper part of the tunnel-shaped heating furnace 120, and a housing 150 is incorporated in the opening. The heating furnace 120 is provided over the four film formation chambers 100 (100a, 100b, 100c, 100d). The heating furnace 120 is provided from the upstream side of the film forming chamber 100 a located upstream in the transport direction of the substrate 200 in order to preheat the substrate 200. That is, the heating furnace 120 is provided across the preheating unit 12 and the film forming unit 13.

  The substrate 200 is heated while being transported through the heating furnace 120 by the transport conveyor 110. When the film is formed on the substrate 200, the inside of the heating furnace 120 is maintained at substantially the same temperature, for example, 550 ° C.

  In the film forming chamber 100 according to the present embodiment, the fine film forming material 160 is deposited on the substrate 200 to form a film. As shown in FIG. 2, the film forming chamber 100 is provided with a housing 150 and a spray mechanism that sprays mist obtained by forming the film forming material 160 into fine particles inside the housing 150.

  The casing 150 has an exhaust port 152 for exhausting mist on one of the side walls. As shown in FIG. 1, one end of a connection pipe 310 is connected to the exhaust port 152. The other end of the connection pipe 310 is connected to a detoxification device 300 that detoxifies the exhausted mist through a valve 320 that opens and closes the connection pipe 310. The abatement apparatus 300 includes a pump that is an exhaust means. By driving the pump with the valve 320 opened, the inside of the film formation chamber 100 is exhausted from the exhaust port 152 through the connection pipe 310.

  As shown in FIGS. 1 and 2, the film forming chamber 100 has an inlet 151 located on one side wall of the housing for introducing a carrier gas 170 for sending mist onto the substrate 200. One end of a blower pipe 340 is connected to the introduction port 151. The other end of the blower pipe 340 is connected to the blower 330 via a valve 350 that opens and closes the blower pipe 340.

  The housing 150 also has a partition wall 154 that divides the interior of the housing 150 into three spaces. The first space is a spray mechanism arrangement space 158 in which a part of the spray mechanism is arranged. The second space is a mist spray space 159 in which mist is sprayed from the spray mechanism. The third space is an exhaust space 153 connected to the exhaust port 152.

  The casing 150 has an open portion that faces the substrate 200 and allows the mist to flow from the mist spray space 159 onto the substrate 200. The opening part is formed in the lower part of the housing 150. As shown in FIGS. 1 and 3, the open portion is located in the heating furnace 120.

  A predetermined gap is provided between the substrate 200 being transported by the transport conveyor 110 and the open portion of the housing 150. A gap 156 is provided between the side wall on the side where the introduction port 151 is located and the substrate 200. A gap 157 is provided between the side wall on the side where the exhaust port 152 is located and the substrate 200.

  The spray mechanism includes a spray nozzle 130 that atomizes the film-forming material 160 with compressed air. The spray mechanism has a spray port for spraying mist. Specifically, the solution of the film-forming material 160 stored in the tank 140 is pressurized by compressed air from a compressor (not shown) and passed through the passage 141, and the mist that has been atomized from the spray port 131 of the spray nozzle 130. Spray. An opening 155 is formed in the housing 150 corresponding to the position of the spray nozzle 130.

  The spray nozzle 130 is a two-fluid spray nozzle that sprays a mist obtained by mixing two fluids of a film forming material 160 and compressed air. Here, the mist means a state in which droplets having an average particle size of 0.1 μm or more and 100 μm or less are dispersed in a gas. The average particle diameter of the mist is a value calculated by the immersion method.

  However, the spray mechanism is not limited to the spray nozzle 130, and may be one that generates mist using ultrasonic waves. When the mist is generated by the ultrasonic vibrator, the average particle diameter of the mist can be made uniform as compared with the case where the mist is generated by the spray nozzle 130. Therefore, the generated mists aggregate before reaching the substrate 200. This can be suppressed.

As shown in FIG. 3, the spray ports 131 of the plurality of spray nozzles 130 are opposed to the substrate 200 in the housing 150 and arranged in a direction perpendicular to the transport direction of the substrate 200 in a space therebetween. Yes. In FIG. 3, three spray nozzles 130 are arranged at the pitch L _p , but the number of spray nozzles 130 is not limited to three and may be one or more. Further, the direction in which the plurality of spray nozzles 130 are arranged is not limited to the direction orthogonal to the transport direction of the substrate 200, but may be any direction that intersects the transport direction of the substrate 200.

  The number of spray nozzles 130 provided is the amount of mist sprayed per unit time necessary to satisfy the desired tact time of the film forming process of the substrate 200 or the film forming speed necessary for performing the film forming process. It will be changed accordingly.

The distance between the upper end of the heating furnace 120 and the substrate 200 is set to L _h / 4 with respect to the distance L _h between the spray port of the spray nozzle 130 and the upper surface of the substrate 200.

  A part of the carrier gas 170 introduced from the inlet 151 described later is sent to the spray nozzle 130 in order to cool the spray nozzle 130. In order to send the carrier gas 170 to the spray nozzle 130, a cooling fan (not shown) is disposed in the vicinity of the spray nozzle 130.

  The spray nozzle 130 is air-cooled by a cooling fan. Further, a cooling pipe for water cooling (not shown) is provided in the vicinity of the spray nozzle 130. As the cooling water circulates in the cooling pipe, the spray nozzle 130 is water-cooled.

  In this way, by cooling the vicinity of the spray nozzle 130, the solution of the film forming material 160 before being sprayed from the spray nozzle 130 is cooled to a temperature equal to or lower than the boiling point. More preferably, the solution of the film forming material 160 is cooled to about room temperature.

  By this cooling, since the solvent in the solution of the film forming material 160 can be prevented from volatilizing in the spray nozzle 130, the concentration of the solution of the film forming material 160 to be sprayed can be kept constant. Further, solidification of the film forming material 160 due to volatilization of the solvent in the solution of the film forming material 160 in the spray nozzle 130 can be suppressed.

  As a result, since the film can be formed using the film forming material 160 having a constant concentration, the quality of the film formed on the substrate 200 can be stabilized. Further, the clogging of the spray nozzle 130 due to the solidified film forming material 160 can be suppressed.

  As a solution of the film forming material 160, a solution in which a chloride of an inorganic material selected from the group consisting of zinc, tin, indium, cadmium, and strontium is dissolved in a solvent can be used. As the solvent, water, methanol, ethanol, butanol and the like can be used. As the solution of the film forming material 160, for example, an aqueous solution containing zinc acetate, an aqueous solution containing indium tin oxide, an aqueous solution containing tin oxide, or the like can be used.

  However, the solution of the film forming material 160 is not limited to this, and various solutions can be used. The concentration of the film forming material 160 solution is not particularly limited, and is, for example, a concentration of 0.1 mol / L or more and 3 mol / L or less.

  Here, the flow path of the gas in the housing 150 will be described. First, the valve 350 is opened and the carrier gas 170 made of, for example, compressed air blown from the blower 330 is introduced into the mist spray space 159 of the casing 150 from the inlet 151. The carrier gas 170 introduced into the mist spray space 159 flows in the direction indicated by the arrow 171. As the carrier gas 170, for example, nitrogen, oxygen, hydrogen, and a mixed gas thereof can be used. When a carrier gas 170 other than air is used, a carrier gas supply cylinder is attached to the blower 330.

  Mist is sprayed from the spray nozzle 130 into the spray region 162 in the direction indicated by the arrow 161. Mist and carrier gas 170 are mixed with each other in mixing region 181. Thereafter, the mist flows in the direction indicated by the arrow 182 and reaches the open portion. Mist is sprayed onto the main surface of the substrate 200 from the open portion. A region where the mist is sprayed onto the substrate 200 is referred to as a spray region X.

  The mist that has reached the spray region X flows along the main surface of the substrate 200. Specifically, the mist flows in a direction indicated by an arrow 183 between a facing surface that is a part of the partition wall 154 and that faces the main surface of the substrate 200, and the main surface of the substrate 200. A region where the mist flows in the direction indicated by the arrow 183 is referred to as a flow channel region Y.

  The mist that has passed through the flow path region Y flows in the direction indicated by the arrow 184 in the exhaust space 153. A region where the mist is directed from the main surface of the substrate to the exhaust port 152 in this way is referred to as an exhaust region Z. The mist that has passed through the exhaust space 153 and has reached the exhaust port 152 is rendered harmless by the detoxifying device 300 and discharged to the outside as the exhaust gas 180. At this time, the valve 320 shown in FIG. 1 is opened. In addition, in FIG. 2, the abatement apparatus 300 is not illustrated.

  The spray area X, the flow path area Y, and the exhaust area Z constitute an open portion. In each of the plurality of film forming chambers 100 (100a, 100b, 100c, 100d), the mist flows from the spray mechanism through the opening portion toward the exhaust port 152.

  As shown in FIG. 1, mist flows in the film forming chamber 100a as indicated by an arrow 400. In the film forming chamber 100b, mist flows as indicated by an arrow 410. In the film forming chamber 100c, mist flows as indicated by an arrow 420. In the film forming chamber 100d, mist flows as indicated by an arrow 430.

  As described above, the substrate 200 passes through the vicinity of the open portion while the mist is flowing, so that the substrate 200 is formed. In the film forming apparatus 10 of the present embodiment, the transfer conveyor 110 is provided so that the substrate 200 passes through the vicinity of the open part.

  The substrate 200 is transferred by the transfer conveyor 110 so as to sequentially pass through the spray region X, the flow channel region Y, and the exhaust region Z in each of the plurality of film forming chambers 100 (100a, 100b, 100c, 100d). . The substrate 200 is formed by depositing fine particles of the film forming material 160 on the main surface while passing through the spray region X, the flow channel region Y, and the exhaust region Z.

For example, the substrate 200 is formed with a plurality of films such as a SiO ₂ film as an alkali barrier layer and a transparent conductive oxide (TCO) as a transparent conductive film. Note that the alkali barrier layer is for preventing performance degradation of the solar cell due to alkali contained in the substrate 200. Therefore, when the substrate 200 is made of a material that does not contain much alkali, the alkali barrier layer need not be formed.

When different types of films are formed on the substrate 200 as described above, mists made of various film forming materials are used in the plurality of film forming chambers 100 (100a, 100b, 100c, 100d). For example, a mist using SiO ₂ as the film forming material 160 is used in the film forming chamber 100a, and a mist using SnO ₂ as the film forming material 160 is used in the film forming chamber 100b.

  Therefore, the mist that has flowed into the heating furnace 120 from the gap 157 in any one of the plurality of film formation chambers 100 (100a, 100b, 100c, 100d) is released from the gap 156 in the other adjacent film formation chamber 100. When mixed in 100 and reaches the spray region X, the quality of the film to be formed is degraded.

  Therefore, in the film forming apparatus 10 according to the present embodiment, the exhaust flow rate from the exhaust port 152 is set to be larger than the inflow flow rate into the housing 150 by the operation of the pump as the exhaust means. As a result, since the inside of the housing 150 is maintained at a negative pressure, the mist sprayed from the spray nozzle 130 and flowing toward the exhaust port 152 through the open portion flows out from the gap 157 into the heating furnace 120. Can be suppressed.

  By doing in this way, in each of the several film-forming chamber 100 (100a, 100b, 100c, 100d), mixing of mist can be suppressed and a several high quality film | membrane is continuously formed on the board | substrate 200. A film can be formed.

More preferably, the exhaust gas flow rate is not less than 3 times and not more than 10 times the total flow rate of the flow rate of the mist sprayed from the spray mechanism and the flow rate of the carrier gas 170 introduced from the introduction port 151. In this embodiment, the total flow rate of the flow rate of the mist sprayed from the spray mechanism and the flow rate of the carrier gas 170 introduced from the introduction port 151 is 1 m ³ / min, and the exhaust flow rate is 4 m ³ / min.

  If the exhaust flow rate is made smaller than three times the total flow rate, the ratio of mist in the exhaust becomes high and the temperature of the exhausted gas becomes high, so that the heat resistance required for the connecting pipe 310 and the abatement apparatus 300 increases. It is not preferable. If the exhaust flow rate is larger than 10 times the total flow rate, the capacity of the pump as the exhaust means increases, which is not preferable.

  By setting the exhaust flow rate to be 3 times or more and 10 times or less of the total flow rate, it is possible to continuously form a high-quality film on the substrate 200 while making the film forming apparatus 10 compact and reducing the apparatus cost.

When forming a transparent conductive film made of SnO ₂ , the temperature in the heating furnace 120 is preferably 450 ° C. or higher and 600 ° C. or lower, and more preferably 520 ° C. or higher and 580 ° C. or lower.

  When the temperature in the heating furnace 120 is lower than 450 ° C., the film formation rate is remarkably lowered by extending the drying time of the mist adhering to the substrate 200. On the other hand, when the temperature in the heating furnace 120 is higher than 600 ° C., the solvent contained in the mist volatilizes before reaching the substrate 200 in a part of the mist and reaches the substrate 200 by losing the film forming performance. As a result, the amount of mist is reduced and the film formation rate is significantly reduced.

  In order to form a uniform film on the substrate 200 by the mist generated by the above configuration, the mist needs to reach the entire surface of the substrate 200. Here, the spray region of the spray nozzle 130 will be described.

FIG. 4 is a schematic diagram showing the outer shape of the spray region of the spray nozzle used in the film forming apparatus according to the present embodiment. As shown in FIG. 4, the spray area 162 of the spray nozzle 130, in a point distant distance L _h from the spray port of the spray nozzle 130, and has an outer elliptical.

Specifically, the length of the major axis has a L _W, elliptical length of the minor axis is L _T. That is, the spray region 162 has a longitudinal direction parallel to the major axis and a lateral direction parallel to the minor axis. The zero point in FIG. 4 is an intersection of the major axis and the minor axis, and is a position immediately below the center of the spray nozzle 130 in the vertical direction.

  FIG. 5 is a graph showing the relative spray strength in the longitudinal direction of the spray region of the spray nozzle according to the present embodiment. FIG. 6 is a graph showing the relative spray strength in the short direction of the spray region of the spray nozzle according to the present embodiment.

  In FIG. 5, the vertical axis represents the relative spray strength (%), and the horizontal axis represents the position (mm) from the zero point in the longitudinal direction of the spray region. In FIG. 6, the vertical axis represents the relative spray strength (%), and the horizontal axis represents the position (mm) from the zero point in the short direction of the spray region.

As shown in FIG. 5, at the point where L _h = 300 mm, the relative spray strength in the longitudinal direction of the spray region 162 of the spray nozzle 130 increases as the distance from the zero point increases to 100%, and then reaches 0%. As it goes away from the point, it descends to 0%.

As shown in FIG. 6, at the point where L _h = 300 mm, the relative spray strength in the short direction of the spray region 162 of the spray nozzle 130 is 100% at the zero point, and decreases as the distance from the zero point increases. It is 0%.

  Thus, in the spray region 162, the mist spraying strength is weaker at the end portion than just below the center of the spray nozzle 130. This tendency is the same when a plurality of spray nozzles 130 are provided.

  FIG. 7 is a graph showing the comparative spraying strength in the longitudinal direction of the spray region when 11 spray nozzles are arranged so that the longitudinal direction of each spray region is in a line with a pitch of 100 mm. FIG. 8 is a graph showing comparative spray strength in the longitudinal direction of the spray area when nine spray nozzles are arranged with a pitch of 120 mm so that the longitudinal direction of each spray area is aligned. FIG. 9 is a graph showing the comparative spraying strength in the longitudinal direction of the spray region when the pitch is 150 mm and eight spray nozzles are arranged so that the longitudinal direction of each spray region is in a line.

  7 to 9, the vertical axis represents the comparative spraying intensity (%), and the horizontal axis represents the position (mm) from the zero point in the longitudinal direction of the spray region arranged in a line. The comparative spray strength (%) indicates the spray strength when a plurality of spray nozzles are arranged at each pitch, with the maximum value of the relative spray strength of one spray nozzle as 100%. .

As shown in FIGS. 7 to 9, at the point where L _h = 300 mm, when the spray nozzle was arranged with a pitch of 120 mm, the comparative spraying strength in the longitudinal direction of the spray region was relatively uniform. Thus, by uniformly adjusting the pitch of the spray nozzles 130 and making the mist spray strength on the substrate 200 uniform, a film having a uniform film thickness can be formed on the substrate 200.

  Hereinafter, a film forming apparatus according to Embodiment 2 of the present invention will be described. In addition, since the film-forming apparatus which concerns on this embodiment differs from the film-forming apparatus 10 which concerns on Embodiment 1 only in providing a ventilation mechanism, description is not repeated about another structure.

(Embodiment 2)
FIG. 10 is a cross-sectional view showing the configuration of the spray mechanism and the air blowing mechanism of the film forming apparatus according to Embodiment 2 of the present invention. FIG. 11 is a view of the spray mechanism and the air blowing mechanism of FIG. 10 as seen from the direction of the arrow XI.

  As shown in FIG. 10, in the film forming apparatus according to Embodiment 2 of the present invention, the film forming chamber 100 is configured so that the mist sprayed from the spray mechanism is a substrate in a direction orthogonal to the transport direction of the substrate 200 in plan view. It further has an air blowing mechanism directed to the end of 200. However, the position on the substrate 200 where the air blowing mechanism directs the mist is not limited to the end in the direction orthogonal to the transport direction of the substrate 200, and the transport direction of the substrate 200 in plan view where the plurality of spray nozzles 130 are located. What is necessary is just the edge part in the said direction to cross | intersect.

  In the present embodiment, the blower mechanism includes an air nozzle 190 that ejects compressed air as a supplementary gas. The air nozzle 190 has a plurality of jet outlets 191. The jet nozzle 191 of the air nozzle 190 faces the substrate 200 and is located around the spray port 131 of at least one of the plurality of spray nozzles 130 in plan view.

  The film forming apparatus according to the present embodiment includes two air nozzles 190. The outlets 191 of each of the two air nozzles 190 are around the spray port 131 of the spray nozzle 130 located at both ends of the plurality of spray nozzles 130 arranged so that the longitudinal direction of each spray region is in a line. Is arranged. Therefore, the mist ejected from the spray nozzles 131 of the spray nozzles 130 located at both ends is accelerated and sent by the compressed air ejected from the jet nozzle 191 of the air nozzle 190 toward the end of the substrate 200.

  That is, the two air nozzles 190 cause the film forming material 160 sprayed from the plurality of spray nozzles 130 to reach the substrate 200 with the distribution corrected. In the present embodiment, the air nozzle 190 is used for the air blowing mechanism. However, the air blowing mechanism is not limited as long as the mist can be directed to the substrate 200, and may be a nozzle that ejects carrier gas, for example. Further, the number of air nozzles 190 is not limited to two, and one or more air nozzles may be provided.

The effect when the air nozzle 190 was provided was confirmed. The pitch L _p was 120 mm, and 10 spray nozzles 130 were arranged so that the longitudinal direction of each spray region 162 was in a line, and the open portion was 1200 mm.

  FIG. 12 is a graph showing the distribution of the amount of mist reached in the longitudinal direction of the spray regions arranged in a line. In FIG. 12, the vertical axis indicates the amount of mist that reaches the substrate 200 (cc / min), and the horizontal axis indicates the position (mm) from the center in the longitudinal direction of the spray regions arranged in one row. .

  As shown in FIG. 12, when compressed air was ejected from the air nozzle 190 at a flow rate of 30 L / min or 40 L / min, it was confirmed that the amount of mist reaching the end of the substrate 200 was increased. .

  FIG. 13 is a graph showing the distribution of the sheet resistance value of the substrate in the direction orthogonal to the transport direction. In FIG. 13, the vertical axis indicates the sheet resistance value (Ω / □), and the horizontal axis indicates the position (mm) from the center of the substrate in the direction orthogonal to the conveyance direction. Further, the case where the complementary gas flow rate is 30 L / min is indicated by a solid line, and the case where no complementary gas is flowing is indicated by a dotted line.

  As shown in FIG. 13, when the air nozzle 190 is not provided, the sheet resistance value at the end of the substrate 200 is remarkably increased. This is because a thin film having a sufficient film thickness is not formed at the end of the substrate 200.

  On the other hand, when compressed air is ejected from the air nozzle 190 as a complementary gas, an increase in the sheet resistance value at the end of the substrate 200 is suppressed. It was confirmed that a transparent conductive film that can be used as a solar cell was formed with a uniform film thickness over the entire substrate 200.

  In the present embodiment, the jet nozzles 191 of the air nozzle 190 are arranged only around the spray ports 131 of the spray nozzles 130 arranged at both ends. However, the arrangement of the jet nozzles 191 of the air nozzle 190 is not limited to this. For example, you may arrange | position around the spray nozzle 131 of all the spray nozzles 130. FIG. In that case, the ejection amount from the ejection port 191 of the air nozzle 190 disposed around the spray port 131 of the spray nozzle 130 disposed at both ends is made larger than the ejection amount from the ejection port 191 of the other air nozzle 190. Thus, a thin film having a uniform thickness can be formed on the substrate 200.

  In the present embodiment, since compressed air is ejected from the ejection port 191 of the air nozzle 190, it is three times the ejection flow rate from the air nozzle 190 compared to the exhaust flow rate of the film forming apparatus 10 according to the first embodiment. The exhaust flow rate is set high in the range of 10 times or less. By doing so, since the inside of the housing 150 can be maintained at a negative pressure and mixing of mist can be suppressed in each of the plurality of film formation chambers 100, a plurality of films having a uniform film thickness can be formed on the substrate 200. A film can be continuously formed with high quality.

  It should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  DESCRIPTION OF SYMBOLS 10 Film-forming apparatus, 11 Input part, 12 Preheating part, 13 Film-forming part, 14 Slow cooling part, 15 Taking-out part, 100, 100a, 100b, 100c, 100d Film-forming chamber, 110 Conveyor, 111 Conveyor belt, 112 Pulley , 113 drive shaft, 120 heating furnace, 130 spray nozzle, 131 spray port, 140 tank, 141 passage, 150 housing, 151 introduction port, 152 exhaust port, 153 exhaust space, 154 partition wall, 155 opening, 156, 157 gap 158 spray mechanism arrangement space, 159 mist spray space, 160 film forming material, 162 spray region, 170 carrier gas, 180 exhaust gas, 181 mixing region, 190 air nozzle, 191 jet outlet, 200 substrate, 300 abatement device, 310 Connecting pipe, 320, 350 valve, 330 blower, 40 blower tube, X-injected region, Y fluid channel area, Z exhaust region.

Claims (4)

Transport means for transporting the substrate along the transport path;
A plurality of film forming chambers positioned so as to line up in the transfer path;
A heating furnace that is positioned in a tunnel shape along the transfer path so as to connect adjacent film forming chambers among the plurality of film forming chambers, and surrounds and heats a substrate that sequentially passes through the plurality of film forming chambers;
An exhaust means for exhausting the inside of each of the plurality of film forming chambers,
Each of the plurality of film forming chambers includes a casing and a spray mechanism that sprays mist obtained by forming a film forming material into fine particles in the casing.
The housing has an exhaust port located on one side wall and connected to the exhaust means, and has an open portion in the heating furnace facing the substrate that sequentially passes through the plurality of film forming chambers. And
The mist flows from the spray mechanism through the opening to the exhaust port in each of the plurality of film formation chambers,
The exhaust flow from the exhaust port by the exhaust means is much larger than the inlet flow into the housing,
The spray mechanism comprises a plurality of spray nozzles each having a spray port for spraying the mist,
The spray ports of each of the plurality of spray nozzles are opposed to the substrate and are spaced apart from each other in a direction intersecting the transport direction of the substrate in plan view,
The film formation chamber further includes a blower mechanism that directs the mist sprayed from the spray mechanism toward an end portion of the substrate in the direction intersecting the transport direction of the substrate in a plan view . Each of the plurality of film forming chambers further includes an introduction port located on one side wall of the housing for introducing a carrier gas for sending the mist onto the substrate,
2. The composition according to claim 1, wherein the exhaust flow rate is not less than 3 times and not more than 10 times the total flow rate of the flow rate of the mist sprayed from the spray mechanism and the flow rate of the carrier gas introduced from the introduction port. Membrane device.   The film forming apparatus according to claim 1, wherein the spray mechanism sprays the mist obtained by atomizing the film forming material with compressed air. The air blowing mechanism is composed of an air nozzle having a plurality of jet ports for jetting compressed air,
2. The film formation according to claim 1 , wherein the plurality of ejection ports are positioned around the spray ports of spray nozzles that face the substrate and are located at both ends of the plurality of spray nozzles in a plan view. apparatus.

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